1. Field of the Invention
This invention relates to a method of extracting a known good die (KGD) from a test carrier without damaging bond pads on the die and to a tool for extraction of the die from the test carrier.
2. Brief Description of the Prior Art
The electronics industry is presently developing technologies for multichip modules (MCMs). A multichip module is a hybrid composed of several very large scale integrated circuits. In order that the MCM become a successful manufacturing technology, there must be a readily available source of known good dice (KGD). KGD are dice that have been burned in and tested at temperatures that the customer specifies passed the required electrical testing necessary to demonstrate the quality and reliability of the dice. When MCMs are built with dice that have not been screened, the process yield drops off in proportion to the number of dice in the MCM. The larger the number of dice, the poorer the yield. If any of the dice are defective, the entire module will fail electrical test.
Dice have been tested in the prior art to identify KGD by, for example, applying tabs to the bond pads of the dice and then cutting the tabs after testing the dice, leaving a portion of the tab attached to each bond pad. This results in the remaining portion of the tab extending from the pad and being available for flip tab bonding. This method of manufacture of KGD is very costly and hard to perform.
Known good dice have also been tested by applying tabs to the die pads and then extracting all of the tab bonds together subsequent to testing. The application force applied to the tabs during extraction must be sufficient to remove all tabs simultaneously, this force being relatively high and generally sufficiently high (generally several hundreds of grams) to result in damage to the die pads and often leaving portions of the tabs secured to the die pads. This is because the total force exerted for tab removal is very large and it is therefore difficult to insure that each tab receives a sufficiently small force applied thereto to prevent damage to the die pads, yet a sufficiently large force to provide tab removal.